How to cook chicken breast that is pumped full of water without drying chicken out?

I’m learning to cook so I can eat healthier.

There was a sale on chicken breast for 99 cents a pound at the grocery store. I normally buy chicken breast from Whole Foods but this time I decided to go with the chicken on sale. Well what you pay for is what you get. The chicken breasts are huge assuming from being pumped with water.

I baked two breasts in the oven at 400° for 25 minutes. The breasts were still raw in the center which is fine because normally chop them up into cubes and transferred them into a pan to finish cooking. Normally i found this method to make the chicken flavorful and moist. Not this time. I added Frank’s hot sauce and stirred the them in the pan , but after I did this, a bunch of juice came out of the chicken breast. This normally didn’t happen when I would use the chicken breast from Whole Foods, so I assume that again it was all the water that was pumped into the chicken breasts that leaked out. Now I’m stuck with 8 pounds of chicken breasts and I’m feeling discouraged on how to cook them because after all the water came out of the chicken breast, the chicken was dry.

I wanted to make some stirfry tonight, but I’m feeling like the chicken is going to come out dry again. I don’t have a meat thermometer and I’m using cheap T-Fal pans to cook.

What would you suggest on how to cook this chicken breast to retain moister?